In practical terms, enhanced oil recovery (EOR) systems relates to different techniques applied for the purpose of recovering as much oil from the underground as possible. A problem related to oil recovery in general is that a significant part of the oil remains in the underground when applying conventional recovery methods. Such methods may include water and gas flooding to keep the pressure high in the reservoir. In order to increase the amount of oil recovered from the underground, different techniques have been developed to increase the amount of oil recovered from already addressed reservoirs.
The conventionally applied techniques vary significantly in complexity, depending on many different factors including e.g. type of oil, the structure and the type of the underground formation, logistics, climate, amount of oil accessible from the well, etc.
The present invention relates to a specific type of oil recovery, namely the type of recovery in which the recovery is aided by the application of enzymes.
US patent application US 2008/0115945 A1 describes a method for recovery of hydrocarbons in a subterranean formation by a dedicated application of enzymatic fluid in that steam or heated fluid containing the enzymes is pumped into the underground oil reservoir to aid in the recovery of oil.
However, enzymes which are effective in relation to oil recovery are often not effective or operative at high temperatures and if they are, they are at least rare and expensive.
A problem related to the above mentioned prior art is therefore that such EOR system and method may become relatively expensive in different ways. A particular problem in relation to the above-mentioned techniques is that enzymes are relatively expensive and that the increased recovery obtained may be relatively low, when compared to the cost related to the applied enzymes, the applied EOR system and the applied recovery method.